TAD Fabric Pocket Segmentation for Pinhole Prevention
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Solution Overview
Problem
Conventional through-air-drying (TAD) fabrics used in papermaking often result in undesirable diagonal patterns and manufacturing stresses that can lead to pinholes and reduced tensile strength in tissue paper products, affecting absorbency, strength, and aesthetic appearance.
Innovation Solution
A TAD fabric with alternating larger and smaller pockets on its surface, formed by raised warp and weft yarns, providing a high open area and air permeability, and a plain weave pattern inside the pockets, which reduces manufacturing stresses and prevents pinholes while maintaining tensile strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional woven TAD fabric with repeating weave pattern is used, then the fabric provides structural integrity and durability, but it creates diagonal patterns and manufacturing stresses that lead to pinholes and reduced tensile strength in tissue paper
Solution Approach 1:
The fabric surface is segmented into distinct pocket regions (first pockets and second pockets) with different sizes and configurations. This segmentation breaks the repeating diagonal weave pattern that causes harmful effects, while maintaining the overall fabric structure and durability through the interconnected pocket system.
Solution Approach 2:
Different regions of the fabric surface are given different qualities through the alternating first and second pockets. The first pockets have different dimensions and stress distribution characteristics compared to the second pockets, allowing each region to optimize for reducing specific manufacturing stresses and preventing pinholes while maintaining overall fabric integrity.
2Productivity
If a TAD fabric with high open area is used to improve air permeability and absorbency, then drying efficiency and tissue paper absorbency increase, but fabric strength and structural stability may decrease
Solution Approach 1:
The fabric combines woven yarns forming pocket structures with coordinated floating yarns that span across multiple pockets. This composite structure creates a hierarchical system where the woven base provides structural integrity and the floating yarns reinforce stress points, enabling high open area for air permeability while maintaining fabric tensile strength.
Solution Approach 2:
The fabric structure nests multiple functional elements within the pocket regions: the woven yarns form the pocket boundaries, floating yarns are positioned within and across pockets to provide reinforcement, and the coordinated arrangement creates nested layers of structural support that maintain strength despite high open area.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The fabric achieves high air permeability and a distinct pattern on tissue paper, enhancing absorbency and strength while preventing pinholes, resulting in improved tissue paper quality.
Implementation Method 1
a flow of heated air, directed against the web and through the TAD fabric or belt, dries the web to a desired degree
Implementation Method 2
a air flow, brought about by vacuum or suction, which deflects the web and forces it to conform, at least in part, to the topography of the TAD fabric or belt
Data Source
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AI summary
A through-air-drying (TAD) fabric for producing tissue paper and related products on a papermaking machine comprising a plurality of warp yarns interwoven with a plurality of weft yarns to produce a paper-side surface pattern characterized by alternating first pockets (219, 220) and second pockets (200). The first and second pockets are bounded by raised warp yarns and raised weft yarns produced by knuckles in the fabric pattern. The first pockets are preferably larger in area than the second pockets. The fabric base weave in the interior of the first pocket is preferably a plain weave pattern. The interior of the second pocket may also be bisected by a raised weft yarn.